Combined lathe-center and dog



A. E. PEARSON.

COMBINED LATHE CENTER AND DOG.

APPLICATION FILED MAR. 29, I920.

Patented Jan. 4, 1921.

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I irso ST res ARTHUR E. PEARSON, O1 MUSKEGON, MICHIGAN.

Specification of Letters Patent.

Patented Jan. a, M3 21.

Application filed. March 29, 1920. Serial No. 369,798.

T 0 all whom it may concern Be it known that l, ARTHUR E. PEARSON, a citizen of the United States, residing at hluskegon, in the county of Muskegon and State of Michigan, have invented certain new and useful Improvements in Combined Lathe-Center and Dog, of which the following is a specification.

My invention relates to improvements in centering mandrels for use upon metal lathes in the turning and finishing of tubular implements of iron, and other metals, and its objects are: first, to provide a means whereby an article may be held perfectly centered at the head end of the lathe; second, to provide a means whereby a hollow mandrel, as the antifriction sleeves on the wrist pins of internal combustion engines may be properly and fully finished over its entire surface without the necessity of removing it from the lathe at any time during the process of forming and polishing; third, to provide a means whereby any. and all inclination of the lathe center, or the material carried upon the center to tremble when being formed or finished, is eliminated.

I attain these objects by the mechanism illustrated in the accompanying drawing, in which Figure 1 is a longitudinal section of what 1 term my perfected, or idle center machine. Fig. 2 shows the end of a revoluble center for a lathe with my securing elements in place, and, Fig. 3 is a front end elevation of a lathe center with my securing element in place.

Similar reference characters indicate similar parts throughout the several views.

I apply this invention to two forms of lathe center construction; the one to be known as an idle center construction, and the other as a revoluble center construction, it being understood that the centers are for use upon the head'or driving end of the lathe.

It is well known that it is all but impossible to render a revoluble center absolutely steady when forming or finishing articles thereon, and especially with annular articles, and to overcome this I have provided a stationary center as shown in Fig. 1. In this construction I provide a firm support ing frame or standard 4, into which 1 secure a proper lining, preferably of steel, as shown at 5, and this bearing is made annular and properly fitted to receive and support the center 6, which is so clamped in place that it cannot revolve with the shaft 2.

The shaft 2 has a round opening about three fourths'of the way through it. longitudinally, and a slotted opening, 11, the1ice through to the end, in which the securing element 8 is pivotally secured, as at 9, and a central core 3 is inserted in this opening, said core having a thin, wedge formed end, 3, within the shaft that is designed to be forced over the corresponding incline on the supporting element to hold this element firmly locked in place when properly connected with the article to be turned, as 15.

The shaft 2 and its core 3 are made to revolve by means of the pulley 1, which is held rigidly in place by means of a key 12 anchored in ,the pulley and passing through the opening 14 in the shaft 2 and into the slot 13 in the core 3 and so adjusted that the core may be easily moved longitudinally to lock and release the supporting element 8 as hereinbefore intimated.

I place an antifriction bushing 7, between the shaft 2 and the center 6, and a second like bushing 16 between the shaft and the bushing 5 so the shaft may be made to revolve freely without revolving the lathe center.

lVhen hanging an article, as the annular sleeve 15, upon this center the core 8 is drawn, relatively, to the left and the part 8 is allowed to drop baekwardly, as per its dotted lines in Fig. 2, so the point a may be passed into the sleeve and be thrown outwardly, as bythe spring 10, into the opening a in the sleeve. By this means the sleeve will be made to revolve but the center 6 will not revolve, thus the end of the sleeve must revolve without the least jar, as the only revolving element in the machine head is the shaft 2 and its core.

With the revolving center the core 2 is dispensed with and the center 6 is provided with a slotted bushing 2 into which the securing element 8 is pivotally mounted, as at 9, and the slotted sleeve is held in place by means of any available fastening, as the set screw 6, and the object 15 is held by the point a as in Fig. 1.

While in the description I have made use of the words lathe centers, &c., the form of centers shown in Fig. 1 is designed expressly for use upon grinding machines, where an annular, or hollow sleeve is designed to revolve slowly and be finished by the use of a swiftly revolving emery, or other available grinding wheel, and is used to avoid trembling, clattering, &c., and to insure perfectly ground sleeves of exact even thickness and uniform construction, though it may, if desired, be used with equal success upon slowly revolving lathes where too much friction will not be exercised upon the center. In this instance the entire center revolves with the mandrel and when the point a of the latch 8 passes into the hole a in the tubular shaft 15 the spring 10 looks the latch. 8 firmly in place without the necessity of using the auxiliary locking device 3, necessary in the coi'istruction shown in Fig. 1, by reason of the resistance of the stationary center 7 producing sul'licient added strain upon the latch 8 to disconnect it from the shaft 15.

What I claim new in the art, is:

1. In a combined lathe center and dog, a supporting element, bushing secured within said support, a lathe center securely mounted within said bushing, a hollow shaft mounted within the center and having a slotted end, a securing element pivotally mounted in said slotted end, means for holding the securing element in normal position, and an endwise reciprocable core within the shaft for holding the securing element locked in place, and means for revolving the shaft without revolving the lathe center.

2. In a combined lathe center and dog, a supporting standard, bushing mounted in said standard, a lathe center mounted within the bushing, an antifriction bushing mounted within the lathe center, a revoluble shaft Within the antifriction bushing, a securing element pivotally mounted in the end of the shaft, and means for locking said securing element firmly in place.

3. In a combined lathe center and dog for turning and finishing piston pin sleeves, a center having a slotted bushing in the end, a securing element pivotally mounted in said bushing, said element having a right angled offset thereon, to pass into the opening through the side of the sleeve, and means for actuating said element and looking it in place.

4. In a combined lathe center and dog for turning and finishing piston pin sleeves, a

center having a central slotted bushing in one end, a securing element pivotally mount ed in said sleeve, the free end of said element formed into an integral pin standing at ri ht angles with the body of the element, and means for securely attaching said pin to the sleeve to revolve the sleeve for turning and finishing it.

5. In a combined lathe centeraud dog, a supporting element, a center secured in said element, a hollow shaft having short lateral slot through, one side near one end, said shaft revolubly mounted in the supporting element and center, and having a longitudinal slot in one end, a securing element pivotally mounted in said slot, an integral. pin extending at a right angle from one end of said element, a longitudinally movable core within the hollow shaft, said co "e having a long slot in one side, a driving pulley mounted upon the shaft, and a key anchored in the hub of the pulley, passing through the slot in the shaft and slidably connected in the slot in the core, and means whereby the core may be made to lock the securing element firmly in position to secure an article to be turned and polished with the lathe.

Signed at Muskegon, hlichigan, hflarch l (3, 1920.

ARTHUR E. PEARSON. 

